rework analyzer_cli to use ContextBuilder getAnalysisOptions

pkg/analyzer_cli/test/data/flutter_analysis_options/somepkgs/flutter/lib/material.dart

Index: pkg/analyzer_cli/test/data/flutter_analysis_options/somepkgs/flutter/lib/material.dart
diff --git a/pkg/analyzer_cli/test/data/flutter_analysis_options/somepkgs/flutter/lib/material.dart b/pkg/analyzer_cli/test/data/flutter_analysis_options/somepkgs/flutter/lib/material.dart
new file mode 100644
index 0000000000000000000000000000000000000000..6eb79ca9a406fe6652e442858d9037ffa3ed5728
--- /dev/null
+++ b/pkg/analyzer_cli/test/data/flutter_analysis_options/somepkgs/flutter/lib/material.dart
@@ -0,0 +1,13 @@
+import 'package:meta/meta.dart';
+
+class FloatingActionButton {
+  /// The widget below this widget in the tree.
+  final Object child;
+
+  /// Creates a floating action button.
+  ///
+  /// Most commonly used in the [Scaffold.floatingActionButton] field.
+  const FloatingActionButton({
+    @required this.child,
+  });
+}